The goals of the project are to couple diagnostic probe development to physical map locations as well as genetic loci that are being compiled by the genome project. Recognized and accepted DNA markers would serve as useful tools for gene mappers as well as valuable diagnostic reagents for clinical cytogeneticists. The advantages to developing a well organized set of probes whose physical and genetic loci are recognized by the genome project are: * This set of probes could serve as a set of reference markers to be used in hybridization mapping of previously unmapped genes. * The integration of diagnostic probe sets into the genome database will facilitate the understanding of the reagents and expedite their use. * New information generated from the genome community can readily be integrated into the probe set. The second goal of this project is to continue to develop fluorescent chemistries that will enable us to more readily detect the probes to be developed.